If it is what is what rather than dimensions you are trying to get your head around, if you have not already done so,
then you could do worse than look at the close up of the 9Q on p105 and the part-dismantled 9Q on page 118 of EM Johnson's book.

Simon

Last edited by 9E on Tue Jul 02, 2019 5:28 pm, edited 1 time in total.

....If anyone can produce a good clean GA of the 9P, I would be happy to pay costs. The drawing in Johnson’s book is very frustrating to try and interpret. ...

I have scanned the MOSI drawing in Johnson vol.2 and can zoom in well enough to read at least some of the measurements, but a clean GA (and its related drawings) would be better. At the time when I bought the 9Q GA (excellent as a full-res colour digital download, by the way) from SSPL, I did ask the image licensing officer at the Science Museum Group if he could help me track down the 9P one, and he said he would ask his colleague about availability. Not had any comeback so far.

In the meantime, the Brassmasters inside motion etches (plus some ex-Finney brass eccentrics out of the T9 kit) have arrived and now begins the head-scratching process of tailoring the etch parts to fit. The ex-Finney eccentrics speak for themselves and are easy to use, but the lead axle crank webs - which are also circular - are not much bigger and I can see a fine old time trying to either:

1. adapt what are etched eccentric cams into cranks! or
2. use the T9 cast brass cranks, but severely reduce the webs (which are massive) to something approximating the 9P/B3 shape.

The B3/1 frames have been marked out for CSB pivots using the suggested measurements given on the CLAG website, with one drill bit snapped so far to show for it.

I know it’s not the purist’s way, but why not simply drive the internal valve gear from the Finney eccentrics, with rockers connecting to the outside cylinder valves, as per the kit. You simply won’t see the internal pistons, crossheads & con rods working, as they are at the bottom of the frames.

I have represented the top of the internal valve gear on my engine, but I doubt that making the outside valves move will be particularly visible, tucked up under the valance with the drain cock linkages in front.

I know it’s not the purist’s way, but why not simply drive the internal valve gear from the Finney eccentrics, with rockers connecting to the outside cylinder valves, as per the kit...

I had considered this, but......

...You simply won’t see the internal pistons, crossheads & con rods working, as they are at the bottom of the frames.

I have represented the top of the internal valve gear on my engine, but I doubt that making the outside valves move will be particularly visible, tucked up under the valance with the drain cock linkages in front.

.....there is so much open space between the frames in that area that to me it seemed a shame not to try to fill it. In a way, I blame Graham for designing in the partial valve gear with "short-cut" eccentrics in the first place, and I thought why not just go the whole hog? The drawings for it sort-of exist.....

Been a while since any last update, however things are happening in the background. As you will have seen from Graeme's (3279) thread, there is progress towards bringing the self-trimming tender etch to market and my New Year's resolution is to crack on with the B7 and B3-2 test builds.

In the meantime, thought you'd like to see this, courtesy of Tony Wright's camera at the Southampton show:

The prototype build has returned from the paint shop (Ian Rathbone) and is seen here posed on Grantham's turntable.

Drooling here. Mine is, sadly, still in its box waiting for me to get around to it. But hey!- this Christmas just gone I received a building jig, now just wheels, gears and motor to source and then I can make a start.